
It’s common for both homeowners and renters to use a water filter to make their tap water safe to drink. Filters may be central to a home, attached to a faucet, or used as part of a water filtration pitcher.
Drinking water is preferable to drinking sugary drinks, particularly for people who are trying to lose weight.
Whatever type of filter is in use, it’s important to have new filters on hand so they can be swapped out when necessary.
But, how long do water filters last? Here are some guidelines to help estimate how much water is filtered each day and how often to change the filter.
How Long Does a Typical Water Filter Last?
The most important thing to know about using water filters is that they are designed to filter a set number of gallons of water. The amount of water they filter depends on where they’re used. A whole-house filter may purify 100,000 gallons of water or more before it must be changed, while smaller filters should be changed more frequently.
How Long Does a Carbon Water Filter Last?
Carbon water filters remove impurities and contaminants from water using a process known as adsorption. In layman’s terms, that means that the impurities in water are chemically attracted to the carbon in the filter and stick to it, leaving purified water behind.
A typical carbon water filter may last for anywhere from two to six months. The Environmental Protection Agency cautions that filters should be replaced regularly according to the manufacturer’s instructions. The agency also notes that carbon filters do not remove disease-causing organisms.
What is the Average Life of Non-Carbon Filters?
Carbon water filters, also known as activated charcoal filters, are only one option to purify drinking water. For anybody wondering what’s the easiest way to purify water, here are some other filter types—together with their average lifespan—to consider:
Reverse Osmosis Filters
Reverse osmosis filters are effective at filtering impurities that carbon filters may miss, including bacteria and other living organisms. These filters are more expensive than carbon filters but they do a better job of purifying water.
Because a reverse osmosis filtration system uses multiple filters, you should know how often to change them. Part of the answer depends on how much water you drink and use for other purposes on an average day. The RO membrane may last between two and five years, while the pre-filters should be changed every six months or so.
Ultraviolet Light Filters
Ultraviolet light filters are not filters in the traditional sense. They use—as the name implies—ultraviolet light to purify water and kill up to 99.99% of harmful organisms in water.
On average, ultraviolet lights will last between 9,000 and 10,000 hours assuming that they are on all the time. That works out to about 375 days, or a little over a year. It’s a good rule of thumb to replace UV bulbs every year.

Can Water Filters Be Cleaned?
There are some good reasons to consider cleaning a water filter instead of replacing it outright. Since many water filters come cased in plastic, it is better for the environment to get as much use out of them as possible. Here are some things to keep in mind before cleaning a water filter:
- What type of filter do you have? A sediment filter—commonly used for well water—can be easily cleaned with a solution of water and bleach. Charcoal filters must be partially disassembled to be cleaned.
- Is your filter going to retain the cleaning products used? While it may be less expensive to clean filters, some water filters may not be designed to come into contact with bleach and other cleaners.
- Which cleaners are safe to use? The type of cleaning products that should be used will be dictated by the type of filter and the manufacturer’s recommendations. For example, a reverse osmosis membrane should be cleaned with a combination of high-pH and low-pH products.
Cleaning water filters instead of replacing them can be a good solution, offering the potential to save money and help the environment by using less plastic. The most important thing to remember is to take care not to damage the filter and learn how to clean a water filter properly to ensure that it works after cleaning.
Change or Clean Your Water Filter Regularly
Any water that’s consumed by humans or animals may carry impurities, including things such as heavy metals, chemicals, and disease-carrying organisms. The right filtration system will ensure that the water in any home is safe to drink. By calculating the amount of water you should consume in a day, you can determine how often to change your water filters.
